What are the diagnostic criteria for autism?

The standard diagnostic criteria used in the United States is the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). In Europe, The ICD-10 Classification of Mental and Behavioural Disorders is used, which distinguishes between childhood autism and atypical autism. Both describe autism as characterized by abnormal or impaired social skills, abnormal or impaired communication skills, and repetitive behavior. Using these criteria, it is often difficult to diagnose autism before the age of 2. Links to these diagnostic criteria are provided below.

In summary, the diagnostic criteria are

• impaired social interaction
• impaired communication
• repetitive behaviors or activities
• delay in social interaction, social language use, or imaginative play
• not better accounted for by Rett disorder or childhood disintegrative disorder

Zero to Three has described alternative behaviors for diagnosis, which they describe under disorders of relating and communicating. They would like to have criteria to be able to diagnose autism spectrum and similar conditions at an earlier age. The link provided below goes to their commercial site, which is one of the few sites to give information on their classifications. Another link related to this is the ERIC site which offers Zero to Three's "Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood. Diagnostic Classification: 0-3" as a PDF download, in which many other conditions are discussed, as well.